As to the original question: was RSA prepared for the SWC?
Well, considering what has happened and specially what has not happened, it seems that South Africa was pretty much prepared. But looking at the inferior infrastructure, public transport and rather long distances to travel between venues (compared to Europe for example) I would think, that everything was operating closer to red line, than in many previous SWCs held in 'first world' countries. Durban was just an example as to how many factors were involved:
Foreign Travel Agents: no one with decent knowledge of RSA should have planned for any soccer fan to arrive on a flight scheduled to land 2 hours before the match. Even if bus shuttles were available, how are they supposed to make their way through a traffic jam.
ACSA: they should have made use of the space on the airport available (cargo apron). They should have realized, that 1 fuel bowser available wouldn't be able to cope. Expecting a 30 minute ground time for non scheduled flights is unreasonable, unless it has been in the notams, that fuel might not be available and inbound flights should have enough fuel to be able to relocate to another airport. It is also unreasonable to expect operators to fly into the old Durban airport, since it is closed for civil operations and insurances wouldn't cover any damages.
ATNS / slots: slots for landing should have only been issued, after an outbound flight plan was filed, as to indicate the planning & willingness of the operator to relocate the aircraft.
Air crews: those refusing to move are certainly to blame, too. If confronted with a notam stating the necessity to relocate to another airfield within a certain time, it is rather short sighted to THEN point out, that old Durban is unsuitable. As to the refueling situation, at least those with local knowledge should have expected problems and come prepared.